The control of sea lice in Atlantic salmon by selective breeding

Sea lice threaten the welfare of farmed Atlantic salmon and the sustainability of fish farming across the world. Chemical treatments are the major method of control but drug resistance means that alternatives are urgently needed. Selective breeding can be a cheap and effective alternative. Here, we combine experimental trials and diagnostics to provide a practical protocol for quantifying resistance to sea lice. We then combined quantitative genetics with epidemiological modelling to make the first prediction of the response to selection, quantified in terms of reduced need for chemical treatments. We infected over 1400 young fish with Lepeophtheirus salmonis, the most important species in the Northern Hemisphere. Mechanisms of resistance were expressed early in infection. Consequently, the number of lice per fish and the ranking of families were very similar at 7 and 17 days post infection, providing a stable window for assessing susceptibility to infection. The heritability of lice numbers within this time window was moderately high at 0.3, confirming that selective breeding is viable. We combined an epidemiological model of sea lice infection and control on a salmon farm with genetic variation in susceptibility among individuals. We simulated 10 generations of selective breeding and examined the frequency of treatments needed to control infection. Our model predicted that substantially fewer chemical treatments are needed to control lice outbreaks in selected populations and chemical treatment could be unnecessary after 10 generations of selection. Selective breeding for sea lice resistance should reduce the impact of sea lice on fish health and thus substantially improve the sustainability of Atlantic salmon production.     

关于影响面条食用品质相关因素的探讨

从小麦生产概况、面条发展历史和工艺、国内外对面条食用品质的研究3个方面,分析了我国面条工业发展缓慢的原因,提出了小麦育种-面粉工业-制面工业,3个环节紧密配合,协调发展,才能形成良性循环的新思路。     

Next Generation Cereal Crop Yield Enhancement: From Knowledge of Inflorescence Development to Practical Engineering by Genome Editing

Artificial domestication and improvement of the majority of crops began approximately 10,000 years ago, in different parts of the world, to achieve high productivity, good quality, and widespread adaptability. It was initiated from a phenotype-based selection by local farmers and developed to current biotechnology-based breeding to feed over 7 billion people. For most cereal crops, yield relates to grain production, which could be enhanced by increasing grain number and weight. Grain number is typically determined during inflorescence development. Many mutants and genes for inflorescence development have already been characterized in cereal crops. Therefore, optimization of such genes could fine-tune yield-related traits, such as grain number. With the rapidly advancing genome-editing technologies and understanding of yield-related traits, knowledge-driven breeding by design is becoming a reality. This review introduces knowledge about inflorescence yield-related traits in cereal crops, focusing on rice, maize, and wheat. Next, emerging genome-editing technologies and recent studies that apply this technology to engineer crop yield improvement by targeting inflorescence development are reviewed. These approaches promise to usher in a new era of breeding practice.     

Fatty acid variation among U.S. Runner-type peanut cultivars

Fatty acid composition was determined among seven U.S. runner-type peanut (Arachis hypogaea L.) cultivars: Florunner, Sunrunner, GK-7, Southern Runner, Sunbelt Runner, Okrun, and Langley. Significant year and cultivar differences were found within these fatty acid profiles. Southern Runner had the best oleic to linoleic ratio and iodine values; whereas Florunner, Sunrunner, and Langley were the highest in unsaturated and lowest in saturated and long-chain fatty acids. For the future, breeding programs need to continue developing peanut cultivars with improved oil quality.     

江苏省耐盐生物质能源植物选育和生物柴油制备研究

江苏省有近67万公顷沿海盐土滩涂资源,发展适应这些土地资源的油料植物对促进江苏省生物质能的产业化具有极大的促进作用.本研究针对江苏省土地资源的特点,自2001年,从江苏盐城种植了近10年的美国耐盐油料植物海滨锦葵6万株自然群体中筛选了40个优良单株,并进行了子代测定.目前已经初步选育出了海滨锦葵优良无性系,含油量从原群体平均的18 %提高到23 %.2005年首次从耐盐油料植物海滨锦葵中成功获得生物柴油实验室样品,并已经得到中石化权威机构检测数据.     

基于RFID技术的肉牛养殖质量安全可追溯系统研究

消费者和国际贸易对食品质量的要求日益提高,而运用监控、预警、追踪、追溯等技术在食品生产的关键环节上进行的质量监控是有效保障食品质量安全的重要手段。研究采用B/S（浏览器/服务器）模式结构体系,基于RFID技术构建了肉牛养殖可追溯系统。系统通过应用RFID技术,实现了对每头肉牛的养殖信息的自动采集,并针对每头肉牛形成可在Internet网络上进行查询的质量追溯档案。解决了牛肉在肉牛养殖环节（牛肉生产源头）上进行以肉牛个体为单位实施质量监控和实现可追溯的问题。     

基于PLC的杂交水稻育种授粉的人造自然风变频调速控制系统

水稻异株授粉靠自然风的吹播,自然风育种靠天时,育种效率较低。在高效杂交水稻育种实验室里,引入人造可控自然风,可实现杂交水稻育种的理想授粉值。为此,设计了人造自然风变频调速系统,用PLC和变频器控制一组风机,模拟自然风的规律,自动控制自然风的产生。给出了系统的硬件电路设计和程序设计。     

中国扎龙湿地水资源监测及评估

水是维系湿地生态系统的基本要素之一.目前,扎龙湿地人工补水、调水缺乏基础资料支撑.扎龙湿地由于其为丹顶鹤和其他鸟类提供繁殖地和迁徙停歇地成为亚洲著名湿地之一.笔者自2005年在扎龙湿地做水资源监测,监测内容主要包括水位和水量的变化以及降水、蒸发等水文气象要素.由于人类活动的长期影响,湿地水资源分流受到严重威胁,如水利工程的建设割裂了区内水资源系统的自流格局与自然分配机制;同时,区域性的干旱,加剧了保护区水资源的短缺矛盾.通过2005-2008年共4 a的水文监测,初步摸清了湿地来水的传播路径,掌握了来水、退水过程和湿地核心区水位变化.     

Fuel provision for nonbreeding deuterium-tritium fusion reactors

Nontritium-breeding D-T reactors have decisive advantages in minimum size, unit cost, variety of applications, and ease of heat removal over reactors using any other fusion cycle, and significant advantages in environmental and safety characteristics over breeding D-T reactors. Considerations of relative energy production demonstrate that the most favorable source of tritium for a widely deployed system of nontritium-breeding D-T reactors is the very large (10 GW thermal) semicatalyzed-deuterium (SCD), or sub-SCD reactor, where none of the escaping³He (> 95%) or tritium (< 25%) is reinjected for burn-up. Feasibility of the ignited SCD tokamak reactor requires spatially averaged betas of 15 to 20% with a magnetic field at the TF coils of 12–13 T.On leave from Dept. of Electronic Engineering, University of Tokyo, Tokyo, Japan.     

论高校德育中促使道德内化的途径

文章阐述了个人的内心信念是道德最根本的作用方式,强调要重视隐性德育的育人作用,加强大学生自身道德修养,促使道德内化。